Manufacture of zinc-dust.



UNITED STATES PATENT OFFICE.

SHERARD OSBORN COWPER-COLES, OF LONDON, ENGLAND.

.MANUFACTURE OF ZINC-DUST.

No. 923,411. Specification of Letters Patent. Patented June 1, 1909.

Application filed August 2, 1907. Serial No. 386,837. I

To all whom it may concern: ple, I have found that it can be utilized for 45 Be it known that I, SHERARD OSBORN Cowthe recovery of zinc and copper from im- PnR-CoLEs, a subject of the King of Great pure zinc-copper alloys as a low voltage and Britain, residing at Grosvenor Mansions, 82 current .density are sufficient for this pur- Victoria street, Westminster, London, Engpose. A convenient form of electrolyte for land,; have invented new and useful Imthis object is sulfuric acid, the impure brass 50 provements in the Manufacture of Zincto be treated being placed in this electrolyte Dust; and I do hereby declare" that the foland in connection with the positive pole of lowing is. a full, clear, and exact description the electric generator composed of the zincof the invention, which will enable others lead couples above referred to. The copskilled in the art to which it appertains to per is deposited at low current density on 55 make and use the same. suitable cathodes and the zinc sulfate which My invention relates to a process for the is formed may be evaporated down to cryseconomical manufacture of what is commertals or the zinc may be deposited by eleccially known as zinc dust, zinc fume, tultz 'trolysis. v

powder and incidentally to the recovery of Zinc dust produced in the manner above 60 copper and zinc from their alloys. described is superior to ordinary commercial According to my invention I deposit zinc zinc dust WhlCh is obtained from the flues of upon a rotatlng cathode under such condizinc distillation furnaces and is also very tions as will insure the said zinc being desuitable for use in the process known as posited 'in a spongy form. ,To this end I Sherardiz'ing. Inpractice it isfound neces- 65 advantageously employ an electrolyte comsary to dry the zinc dust in a reducin atposed of hot or cold caustic soda solution, mosphere to prevent the formation 0? too and anodes of iron or an alloy of zinc and much zinc oxid. v iron known as hard zinc, the zinc sponge Having now particularly. described and being deposited upon an iron disk which is ascertained the nature of my said invention 7 caused to rotate slowly and being removed and in what manner the same is to be pertherefrom continuously by means of one or formed, I declare that what I claim is more scrapers; the current employed may '1. A process for the production of zinc have a density of several hundred amperes dust, consisting in electrodepositing zinc in per square foot. a spongy form and subsequently dryin the 75 The electrolyte may be regenerated in a said spongy zinc in a reducing atmosp ere. separate chamber or vessel and I have found 2. A process for the production of zinc that an economical form of zinc is either dust, consisting in electrodepositing zinc scrap zinc or what is known as hard spelter' from a caustic soda solution upon a revolvobtained from the baths of hot galvanizing ing disk upon which the zinc is deposited in. 0 works. The bars or slabs of zinc are susthe form of a sponge and is continuously pended in the baths or tanks and the zinc v removed, and in then drying the spongy deposited upon the iron electrode. zinc so produced in a reducing atmosphere. 40 In the process of regeneration a considers able amount of electric current is generated. SHERAVRD OSBORN if the hard zinc is coupled to an electro- Witnesses:

negative metal such as lead and this may be C. G. REDFERN,

used for a variety of purposes. For exam- A. ABBOTT. 

